Abstract: In this talk, Prof. Xinjie Yu will share the experiences of online teaching at Tsinghua University since the beginning of February. Ideological and technological barriers will be introduced while we were facing this brand new almost-pure-online-teaching-and-learning situation seriously. Suitable training sessions were designed and carried out for faculties, TAs, and students respectively. Online learning resources, including e-textbooks and MOOCs, were prepared in time. A powerful instantaneous learning outcome feedback tool, the RainClassroom, were deployed. Pedagogical recommendations of online teaching and interactive techniques were provided for fledgling lecturers. A set of criteria for evaluating the interaction were designed. With all these efforts, the massive real-time interactive online teaching pattern was realized in Tsinghua University successively and then propagated to other Chinese universities. At the same time, many of the new interactive scenes were emerged or invented by rapt teachers. So possible influence will be discussed for the future campus teaching at the end of the talk.